move your Zotero folder out of Dropbox. What you're seeing right now is likely still harmless and will stop once that's done, but you can permanently and irretrievably damage your database by placing your Zotero data directory into Dropbox.

Hi there! I keep reading in the Zotero forum that one should NOT move their *entire* Zotero folder (including the sqlite file, for example) to Dropbox. However, I wonder whether that also applies if I *only* use Zotero to store references, i.e. I do not upload PDF files, do not annotate anything, don't take notes etc. I don't even use folders or keywords. I am really just using Zotero "plain vanilla".

Moving the file to Dropbox would have obvious benefits such as the ability to restore to an earlier version in case something went wrong. Let me also add that I used OneDrive for my *entire* Zotero folder (as set in the preferences) for about a year now without any problems. I now need to switch to Dropbox for some other reason and wonder why Dropbox should give me more trouble (at least in the case of OneDrive I think I did not get a pop-up warning me of the "dangers" of using a cloud drive when chancing the directory).

Just to add to my previous comment, I am also not using two instances of Zotero simultaneously and make sure that I always wait a bit for Dropbox to sync before opening Zotero. I suppose whether Zotero syncs the database or Dropbox should not matter at the end of the day? Both should also always be in the same state. Since I only use Zotero for references, my database is also relatively small (30MB). So that makes it easier to follow this protocol.

I have today also tried using Dropbox for my entire Zotero file and the only thing that I noticed was that the file "zotero.sqlite-journal" (along with a folder called TMP, I think) was deleted on Dropbox at some point. But since everything works fine I reckon this is just a regular Zotero operation (perhaps because I have added new items to the database and this is some temporary file created in the process that can be deleted by Zotero once over). Anyway, if that raises any alarm bells and I should *really* stop using Dropbox, I'd appreciate a short warning from someone more knowledgeable in this forum.

Finally, I have actually been thinking of how else I could get what I want, which is basically an option to restore my library to an earlier version (in case I someday really make a mistake and delete *everything* by accident). Why wouldn't Zotero offer this kind of service? I, for one, would be happy to pay for this functionality...

You should stop using Dropbox. This is particularly true if your Dropbox folder is synced across more than one computer. If you're only using it as a back-up tool, chances that things go wrong are smaller, but still not zero.

The PDFs are actually the only part that is _safe_ to store in Dropbox. It's zotero.sqlite that you will corrupt, potentially irretrievably so.

Local versioned back-ups are the easiest way to be able to go back to older. You can, of course, place those in Dropbox et al.

edit: there is no difference between Dropbox and OneDrive; the warning is for Dropbox because that's easy to recognize and widely used.

Thanks for the answer. I changed the path back to my normal HDD. However, I guess that begs the question why OneDrive users are not alerted to this issue. To my mind, Zotero should display a permanent message in the "Files and Folders" tab to alert ALL users to this issue. Dropbox may be the most popular cloud service. But if someone uses another service, they are not aware of the problem at all. Only once I switched to Dropbox and started looking around in the forum did I learn about the hazards of using cloud drives.

Secondly, my Zotero folder actually has around 30 sqlite files named after my home and work computers and with ascending numbers. Is that something I should worry about? I think I may have also lost some "folders" along the way, now that you mention it. I never really used them, but now I noticed that there are none when I think only a few weeks ago I still had a couple (leftovers from when I started out and thought the feature might be useful). Should I make a "clean install" of Zotero and try to export and re-import my library from scratch? Would that get my sqlite back to 100? Do you have any experience whether a corrupted sqlite makes adding references in a Word document slower? (Not that I noticed anything yet, but I thought I try to see how big my problem may become...)

There's little point in worrying about those 30 files now, but they indicate sync conflicts (files changed on both sides) which means it's not at all unlikely that you suffered some damage.

Not an expert on the matter (@adamsmith will know better) but it's important to stop syncing the Zotero DB using cloud drives right now if you have not already. It's probably best to run your DB through https://www.zotero.org/utils/dbfix/ but for this I'd wait for expert advice. The sync conflict files are going to be useless.

edit: No need to reinstall Zotero; in principle an export-datawipe-import should get you a 100% clean DB but you will lose:

1. Any saved searches

2. Depending on what you use for export, your collections

3. Again depending on what you use for export, some data from your references

as there is not currently a 100% round-trip export-import format. I would advice waiting for @adamsmith or others commenting on the use of the BD fixer.